Just my two cents but maybe he feels like he can pass along some MCR-related things that he’d been holding on to because they ARE a band again.
It’s not a ‘I have to keep everything to remember what we were’ - it’s more ‘we are gonna make new things together now’.
Remember the opening line of the very first MCR song was “you’re not in this alone”
No matter how much it feels like it, or how much your brain, other people, or the world wanna make it seem like that’s true
You’re. Not. In. This. Alone.